Electric switch.



No. 653,698. 7 Patented July 17, I900.

I J. T. ROBB.

ELEGTBIC SWITCH.

(Application filed Jan; 51; 1900.)

(No Model.

m: norms PETERS co. PHOTO-LITHO., WASHINGTON, n. cy

UNITED STATES JAMES T. ROBE, OF NEW YORK, N. Y.,

ASSIGNOR TO THE MITCHELL VANCE COMPANY, OF SAME PLACE.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 653,698, dated July 17, 1900. Application filed January 31, 1900. Serial No. 3,418. (No model.)

T at whom, it may concern:

Be it known that 1, JAMES T. RoBB, a subject of the Queen of Great Britain, residing at New York, (Flatbush,) borough of Brooklyn, State of New York, have invented a certain new and useful Improvement in Electric Switches, of which the following is a specification.

My invention relates to new and useful improvements in electric switches adapted particularly for use in connection with bracketarms of chandeliers of those designs in which the employment of socket-switches for the lamps is undesirable or inconvenient. My

[5 switch may be used for any other desired purpose.

The object of my invention is to provide a switch which is simple and cheap in construction, is durable in use,provides a perfect snap action, and is of such proportions as to fit it especially for use with fixtures employing bracket-arms, as it does not in any wayinterfere with the artistic finishing of such fixtures.

When my improved switch is employed in connection with a bracket-arm, the invention also contemplates the provision of improved means for properly securing the sections of the covering-shell in place, whereby the latter will be very firmly retained and cannot be dislodged during the cleaning of the fixture, as is likely to occur with the present devices.

Broadly stated, my improved switch comprises a suitable supportingframe which if used with a bracket-arm may be interposed directly in the line of the tubing, a contact or contacts carried by said frame and insulated therefrom, a movable contact mounted in the frame to reciprocate toward and away from the stationary contact or contacts, a spring tending to force the movable contact away from the stationary contact or contacts, and suitable cooperating cam surfaces moved relatively to each other by the desired keys and arranged to engage the contacts together to maintain them in such engagement or to permit the spring to snap the movable contact away from the stationary contact or contacts.

The invention further comprises a two-part sectional shell inclosing the elements of the switch and held in place with respect to the frame by means of a clamping-collar which forces the shell-sections into tight engagement with a fixed shoulder.

In order that my invention may be better understood, attention is directed to the accompanying drawings, forming a part of this specification, and in which- Figure 1 is alongitudinal section of my improved switch, illustrating its use in connection with a bracket-arm, the section being taken on the line 1 1 of Fig. 2 looking toward the left; Fig. 2, a section on the line 2 2; Fig. 3, an enlarged perspective detail view of the engaging cam-surfaces, showing their position when the movable contact is withdrawn from engagement with the stationary contact or contacts to break the circuit; and Fig. 4, a similar view showing the relation of the camfsurfaces when the movable contact has been moved to close the circuit.

Like numerals represent corresponding parts in the several views. 7

1 is an open ring-like frame having two internally-threaded bosses 2 2, into which are screwed the sections 3 3 of the fixture-arm.

4 is an insulating-block carried by the frame, made preferably of porcelain, and 5 5 8 0 are two spring-metal contacts secured to said block in any suitable way. Screws 6 6 0011* nect with said contacts and permit one of the mains 7 to be properly connected with a break between the contacts, the other main 8 being continuous.

9 is the movable contact securedto a block 10 and arranged to engage the contacts 5 5 to bridge the break and complete the main 7.

It is obvious that one of the sections of the main 7 may be connected to the contact 9 and only a single stationary contact 5 employed; but the described arrangement is preferable. The block 10 is secured to a shank 11-, made rectangular in cross-section (see Figs. 3 and 4) and which is mounted in a tubular boss 12, cast with the frame,the shank passing through a correspondingly-shaped opening in the inner face of said boss, so as to be prevented from turning. The shank 11 has an integral head 13, and surrounding the shank between said head and the end of the boss 12 is a spim1 p n which e ds t n rma ly s nam e eenta sfian Moueted e t e boss 12 is a head 15, which is carried by a stud 16, screw-threaded and receiving the usual turning-key 17. A cap 18 is screwed over the outer end of the boss 12 and holds the two heads 13 and 15 in constant engagement. The head 13 is provided with two came teeth 19 19, each formed with a straight and an inclined edge, and the head 15 is provided with two similarly-arranged cam-teeth 20, except that each of the latter is provided on its end with a notch 21 for receivi the end of the corresponding tooth 19. The teeth of the two heads may be intercalated, as shown in Fig. 3, so that the two heads constitute practicallya continuous cylinder, or the key may be turned to partly rotate the head 15, Where'- upon the inclined edges of the teeth 19 and 20 will be engaged together, causing the head 13 to be moved longitudinally and bringing the contact 9 into engagement with the eontacts 5 5. The ends of the teeth 19 will then enter the notches 21 and hold the contacts in engagement. By continuing the rotation of the key 17 the straight faces of the engaging earn-teeth will be brought past the line of each other, whereupon the spring 14 will retract the contact 9 with a snap action.

When the improved switch is employed in a bracket-arm, it is preferably covered bv a spherical shell made in two sect-ions 22 22, the joint running longitudinally and the edge of one section preferablyoverlapping that of the other, Fig. 2. These sections are engaged by ascrew-threaded collar 23 on one of the bosses 2, which forces them tightly against a shoulder 24 on the other boss, thereby holding the shell securely in place. The shoulder 22% is preferably designed to simulate the collar 23 to preserve the symmetry of the complete device.

,Hevieg 1 0 de c bed my twent es, What I cla m x y J '1. An improved switch, comprising a frame, a pair of stationary contacts, a sleeve or boss,

.a shank movable longitudinally therein, a

movable contact carried by said shank, a head connected to said shank and having a pair of cant-teeth, means for preventing rotation of said head, a spring surrounding the shank 2. An im proved switch,'com prising a; frame,

a pair of stationary contacts, a sleeve or boss, a shank movable longitudinally therein, a movable contact carried bysaid shank, a head connected to said shank and having a pair of camrteeth, means for preventing rotation of said head, a spring surrounding the shank and engaging said head, a rotating head having a pair of cam-teeth, engaging the other canrteeth, and a key for turning the rotating head, one set of said teeth being notched for engagement with the other teeth, substantially as set forth.

3,. The combination with the circular in.- elosing frame of a bracket-arm switch, said frame carrying a stationary shoulder at one side and a collar at its diametrically-opposite side, of a two-part spherical shell inclosing said frame with the split extending longitu: dinally of the frame, said shell being held in position between said shoulder and collar, substantially as set forth.

This speci fication signed and witnessed this 27th day of January, 1900.

JAMES T. ROBB.

Witnesses:

J osEPH RoWELL, ERNEST A. DAVIS. 

